I am unsure if this will repeat beyond the build I finally did finish (by throwing in exact block sums until the order worked itself out, and every item was at //exactly// 100%, with none > 100%).
In any case, if //any// resource is filled beyond 100%, the construction will not finalize. The check appears to loop over every value, check if count == desired, and only returns true if all are equal, rather than count >= desired.